High Rates of Kidney Disease among HIV Positive African
Americans
By
Liz Highleyman
 HIV
positive African Americans have a higher rate of end-stage renal (kidney)
disease (ESRD) than their white counterparts, and -- regardless of race -- people
with HIV and kidney disease may be inadequately treated, according to 3 recently
published studies.
Renal Replacement
Therapy
In
the first study, reported in the November 30, 2007 issue of AIDS, Gregory
Lucas and colleagues compared the need for renal replacement therapy (e.g., kidney
dialysis) in HIV positive and negative African Americans, and described trends
over time in renal replacement therapy and chronic
kidney disease in the setting of HIV infection.
The study included
4509 HIV positive and 1746 HIV negative African American participants in Baltimore
followed between 1988 and 2004. New onset renal replacement therapy was identified
by matching participant identifiers with the U.S. Renal Data System. Chronic kidney
disease was defined as an estimated glomerular filtration rate (GFR) of < 60
mL/min per 1.73 m2 for at least 3 months.
Results •
Incidence
rates for starting renal replacement therapy were as follows: •
125 patients
with AIDS during 9833 person-years of follow-up (standard incidence ratio [SIR]
16.1);
• 51 HIV positive patients
without AIDS during 10,780 person-years of follow-up (SIR 6.9);
•
24 HIV negative individuals during 13,415 person-years of follow-up
(SIR 2.3).
•
Among
HIV positive African Americans, renal replacement therapy incidences were 5.8
and 9.7 per 1000 person-years in the pre-HAART and HAART eras, respectively (adjusted
rate ratio 1.2).
•
Further
analysis showed that chronic kidney disease declined significantly in the HAART
era compared with the pre-HAART era, but the period prevalence increased.
"Nearly
1% of HIV-infected African Americans initiated renal replacement therapy annually,
a rate that was similar in the HAART and pre-HAART eras," the authors wrote.
"While new cases of chronic kidney disease decreased, the prevalence of chronic
kidney disease increased in the HAART era, primarily because survival in those
with HIV-associated chronic kidney disease has improved."
John
Hopkins University, Baltimore, MD; Center for Urban Epidemiologic Studies, New
York Academy of Medicine, New York, NY; Department of Statistics, University of
Haifa, Israel.
End-stage
Renal Disease
As
reported in the November 2007 Journal of the American Society of Nephrology, Andy
Choi and colleagues studied the incidence of ESRD -- defined as kidney failure
requiring dialysis -- among individuals with HIV infection or diabetes. They followed
a national sample of 2,015,891 HIV positive and HIV negative U.S. veterans over
a median period of 3.7 years, starting in 2000-2001 (about 0.8% were HIV positive).
Results •
The age- and sex-adjusted incidence of ESRD (per 1000 person-years) among HIV
positive black patients was nearly an order of magnitude higher than that of HIV
positive white patients, and almost twice that of whites with diabetes.
•
However, ESRD rates were similar among black patients with HIV and blacks with
diabetes.
•
In a multivariate Cox proportional hazards analysis, diabetes was associated with
an increased risk of ESRD among white patients (approximately double), but HIV
infection was not.
•
Among black patients, both HIV and diabetes conferred a similarly increased risk
of ESRD (4- to 5-fold compared with white patients with neither HIV nor diabetes).
"HIV
and diabetes carry a similar risk of ESRD among black patients, highlighting the
importance of developing strategies to prevent and treat renal disease among HIV-infected
black individuals," the authors concluded.
"Our study demonstrated
a striking and unexpected degree of ESRD among HIV-infected persons of black race,"
said Dr. Choi. "Among white patients with HIV, rates of ESRD were far lower
than among blacks and HIV did not confer an increased risk of ESRD. We can think
of few other risk factors for ESRD that are modified to this extent by race."
Inadequate
Treatment of Patients with Kidney Disease
In
the December 15, 2007 issue of Clinical Infectious Diseases, Dr. Choi and
colleagues reported that many HIV positive people with kidney disease do not appear
to be receiving appropriate antiretroviral therapy.
The researchers conducted
a retrospective observational analysis of the medical records of 12,315 HIV positive
patients receiving care through the Veterans Affairs healthcare system who had
established indications for HAART (for example, a low CD4 cell count) and who
received at least 1 serum creatinine measurement.
The investigators collected
data on HAART outcomes, percentage of follow-up time treated with HAART, inadequate
dose adjustment of antiretroviral drugs eliminated by the kidneys, and time to
death.
Although many anti-HIV drugs are metabolized by the liver, the
kidneys play a role in eliminating some antiretroviral medications. It is recommended
that doses of such medications should be adjusted downward in patients with impaired
renal function.
Results
•
Overall,
1041 patients (8.5%) had chronic kidney disease, defined as an estimated GFR <
60 mL/min per 1.73 m2.
•
Factors
associated with a higher risk of chronic kidney disease included black race, older
age, lower CD4 cell count, and hepatitis C virus (HCV) infection.
•
Kidney
disease was also linked to higher rates of AIDS, diabetes, and cardiac problems.
•
Compared
to patients with an estimated GFR ? 60 mL/min per 1.73 m2, HAART exposure was:
•
14% less
likely among patients with GFR of 30-59;
• 24%
less likely among patients with GFR of 15-29;
•
64% less likely among patients with GFR < 15 but not receiving kidney
dialysis;
• 49% less likely among
patients receiving long-term dialysis.
•
At
study entry, 15.4% of patients with chronic kidney disease received HAART unadjusted
for the level of renal function.
•
The
adjusted hazard ratios for death were:
•
1.36 for
patients with an estimated GFR of 30-59 mL/min/1.73 m2;
•
2.17 for
patients with GFR of 15-29;
• 5.97
for patients with GFR < 15 but not on dialysis;
•
1.92 for dialysis-dependent patients.
•
Underexposure and inadequate dose adjustment of antiretroviral drugs explained
22.5% to 35.5% of the excess mortality found among patients with different degrees
of chronic kidney disease.
In
conclusion, the authors wrote, "Underexposure and inadequate dose adjustment
of HAART may contribute to excess mortality among HIV-infected patients with chronic
kidney disease."
San Francisco General Hospital, San Francisco,
CA; University of California, San Francisco, CA; San Francisco Veterans Affairs
Medical Center, San Francisco, CA; Veterans Affairs Puget Sound Healthcare System
and University of Washington, Seattle, WA.
12/07/07 References GM
Lucas, SH Mehta, MG Atta, and others. End-stage renal disease and chronic kidney
disease in a cohort of African-American HIV-infected and at-risk HIV-seronegative
participants followed between 1988 and 2004. AIDS 21(18): 2435-2443. November
30, 2007. AI
Choi, RA Rodriguez, P Bacchetti, and others. Racial differences in end-stage renal
disease rates in HIV infection versus diabetes. Journal of the American Society
of Nephrology 18(11): 2968-2974. November 2007.
AI Choi, RA Rodriguez,
P Bacchetti, and others. Low Rates of Antiretroviral Therapy among HIV-Infected
Patients with Chronic Kidney Disease. Clinical Infectious Diseases 45(12):1633-1639.
December 15, 2007. |
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